Changes in emotional behaviour, spontaneous motor activity and brain polyamine levels following bilateral olfactory bulb ablations in mice

Abstract

Influence of bilateral olfactory bulb ablations on emotional behaviour, spontaneous motor activity and brain polyamine levels in mice was studied. Results are as follows. Bilateral olfactory bulb ablations in mice (O.B. mice) gradually resulted in hyperemotionality. The spontaneous motor activity (SMA) as measured by both photo-cell counters method and open-field test increased during the post-operative period. In O.B. mice, attacking behaviour gradually increased in proportion to the length of post-operative time. The pattern indicated 30% on the 8th day and 44% on the 15th day after operation. In hyperemotional mice which attacked when facing each other on the 15th day, the SMA tested by both photo-cell counters method and open-field test increased as compared with the non-hyperemotional mice in which an attacking response was absent. In O.B. mice, spermine (SPM) levels selectively increased on the 8th day and both polyamine (SPD and SPM) levels increased as compared with the sham mice on the 15th day. SPM levels in hyperemotional mice markedly increased as compared with sham and non-hyperemotional mice on the 15th day after operation.